/**
 * 数组遍历
 */
 let loopArr = ['Maple', 'Jame', 'Tom']
 // value遍历
 for (let val of loopArr) {
     console.log('value遍历: ', val)
 }
 // 索引遍历
 for (let idx of loopArr.keys) {
     console.log('索引遍历: ', idx)
 }
 // 索引+value遍历
 for (let [idx1, val1] of loopArr.entries) {
     console.log('索引: ', idx1, ';值: ', val1)
 }